What Is a Butterfly Needle?

A butterfly needle, also known as a winged infusion set or scalp vein set, is a medical device used for venipuncture and short-term IV infusions.

It’s designed with two plastic “wings” that allow for precise placement and control, making it ideal for patients with small or fragile veins, such as children or the elderly.

Unlike regular straight needles, butterfly needles feature a flexible tubing that connects the needle to a syringe, vacutainer, or IV line.

This structure minimizes movement once the needle is inserted, increasing both accuracy and patient comfort.

👉 Shop butterfly needles on Mudomed:

🔗 Browse Butterfly Needle Collection

Common Uses of Butterfly Needles

Butterfly needles are widely used in clinical and laboratory settings. Typical applications include:

• Blood draws (phlebotomy)

• Short-term IV fluid or medication administration

• Blood collection for PRP (Platelet-Rich Plasma) procedures

• Accessing small, fragile, or difficult veins

• Pediatric and geriatric patients

Because of their ergonomic winged design and stability, butterfly needles reduce the risk of vein damage and improve collection success rates.

For more on needle gauge selection, check out our detailed guide:

👉 21G vs 23G Butterfly Needles: Which One Is Right for Your Clinic

 

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Key Advantages of Butterfly Needles

✅ Better Control and Placement

The winged design allows clinicians to hold and insert the needle with greater precision, especially in delicate veins.

💉 Reduced Hemolysis

Studies show lower hemolysis rates compared to straight needles, which means more accurate lab results.

👵 Ideal for Fragile Veins

Particularly useful for pediatric, elderly, or dehydrated patients where veins may collapse easily.

🌿 Improved Patient Comfort

The thin needle and flexible tubing cause less discomfort during insertion and collection.

 

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Potential Limitations

While butterfly needles are incredibly useful, they do have a few considerations:

• Flow rate is lower compared to larger IV catheters, so they’re not ideal for rapid infusions.

• Short-term use only: typically recommended for up to 5 hours.

• Higher cost per unit than standard needles.

• Needlestick injury risk if the device lacks a safety shield (many modern BD models have built-in safety mechanisms).

Choosing the Right Gauge: 21G vs 23G

The most commonly used butterfly needle sizes are 21G and 23G.

• 21G Butterfly Needles:

  • Larger diameter, faster blood flow

  • Best for adult patients and routine blood draws

  • Preferred when multiple vials are collected

   

• 23G Butterfly Needles:

  • Thinner, gentler insertion

  • Ideal for patients with smaller veins

  • Commonly used in pediatric or elderly populations

   

👉 Learn more in our detailed comparison post:

📖 21G vs 23G Butterfly Needles